WOoW! Absolutely gorgeous image! I can't believe how far we've come. Everytime I look up at the stars, I have to tell myself that it's not just a ceiling to our world but a completely vast universe. Sounds ridiculous but it's easy to just forget.

Discovery's Rainbow Credit: NASA, Ben Cooper (Launch Photography)Explanation: Just one minute before midnight EDT, Friday, August 28, the Space Shuttle Discovery began a long arc into a cloudy sky. Following the launch, a bright and remarkably colorful trail was captured in this time exposure from the Banana River Viewing Site, looking east toward pad 39A at the Kennedy Space Center. On STS-128, Discovery docked with the International Space Station Sunday evening. The 13-day mission will exchange space station crew members and deliver more than 7 tons of supplies and equipment. Of course, the equipment includes the Combined Operational Load Bearing External Resistance Treadmill (COLBERT).

First Image Ever Obtained from Mercury OrbitAt 5:20 am EDT on Mar. 29, 2011, MESSENGER captured this historic image of Mercury. This image is the first ever obtained from a spacecraft in orbit about the Solar System's innermost planet. Over the subsequent six hours, MESSENGER acquired an additional 363 images before downlinking some of the data to Earth. The MESSENGER team is currently looking over the newly returned data, which are still continuing to come down.

WASHINGTON -- Scientists using NASA's Fermi Gamma-ray Space Telescope have detected beams of antimatter produced above thunderstorms on Earth, a phenomenon never seen before.

Scientists think the antimatter particles were formed in a terrestrial gamma-ray flash (TGF), a brief burst produced inside thunderstorms and shown to be associated with lightning. It is estimated that about 500 TGFs occur daily worldwide, but most go undetected.

"These signals are the first direct evidence that thunderstorms make antimatter particle beams," said Michael Briggs, a member of Fermi's Gamma-ray Burst Monitor (GBM) team at the University of Alabama in Huntsville (UAH). He presented the findings Monday, during a news briefing at the American Astronomical Society meeting in Seattle.

Fermi is designed to monitor gamma rays, the highest energy form of light. When antimatter striking Fermi collides with a particle of normal matter, both particles immediately are annihilated and transformed into gamma rays. The GBM has detected gamma rays with energies of 511,000 electron volts, a signal indicating an electron has met its antimatter counterpart, a positron.

Although Fermi's GBM is designed to observe high-energy events in the universe, it's also providing valuable insights into this strange phenomenon. The GBM constantly monitors the entire celestial sky above and the Earth below. The GBM team has identified 130 TGFs since Fermi's launch in 2008.

"In orbit for less than three years, the Fermi mission has proven to be an amazing tool to probe the universe. Now we learn that it can discover mysteries much, much closer to home," said Ilana Harrus, Fermi program scientist at NASA Headquarters in Washington.

The spacecraft was located immediately above a thunderstorm for most of the observed TGFs, but in four cases, storms were far from Fermi. In addition, lightning-generated radio signals detected by a global monitoring network indicated the only lightning at the time was hundreds or more miles away. During one TGF, which occurred on Dec. 14, 2009, Fermi was located over Egypt. But the active storm was in Zambia, some 2,800 miles to the south. The distant storm was below Fermi's horizon, so any gamma rays it produced could not have been detected.

"Even though Fermi couldn't see the storm, the spacecraft nevertheless was magnetically connected to it," said Joseph Dwyer at the Florida Institute of Technology in Melbourne, Fla. "The TGF produced high-speed electrons and positrons, which then rode up Earth's magnetic field to strike the spacecraft."

The beam continued past Fermi, reached a location, known as a mirror point, where its motion was reversed, and then hit the spacecraft a second time just 23 milliseconds later. Each time, positrons in the beam collided with electrons in the spacecraft. The particles annihilated each other, emitting gamma rays detected by Fermi's GBM.

Scientists long have suspected TGFs arise from the strong electric fields near the tops of thunderstorms. Under the right conditions, they say, the field becomes strong enough that it drives an upward avalanche of electrons. Reaching speeds nearly as fast as light, the high-energy electrons give off gamma rays when they're deflected by air molecules. Normally, these gamma rays are detected as a TGF.

But the cascading electrons produce so many gamma rays that they blast electrons and positrons clear out of the atmosphere. This happens when the gamma-ray energy transforms into a pair of particles: an electron and a positron. It's these particles that reach Fermi's orbit.

The detection of positrons shows many high-energy particles are being ejected from the atmosphere. In fact, scientists now think that all TGFs emit electron/positron beams. A paper on the findings has been accepted for publication in Geophysical Research Letters.

"The Fermi results put us a step closer to understanding how TGFs work," said Steven Cummer at Duke University. "We still have to figure out what is special about these storms and the precise role lightning plays in the process."

NASA's Fermi Gamma-ray Space Telescope is an astrophysics and particle physics partnership. It is managed by NASA's Goddard Space Flight Center in Greenbelt, Md. It was developed in collaboration with the U.S. Department of Energy, with important contributions from academic institutions and partners in France, Germany, Italy, Japan, Sweden and the United States.

The GBM Instrument Operations Center is located at the National Space Science Technology Center in Huntsville, Ala. The team includes a collaboration of scientists from UAH, NASA's Marshall Space Flight Center in Huntsville, the Max Planck Institute for Extraterrestrial Physics in Germany and other institutions.

Universe's Not-So-Missing MassScienceDaily (May 24, 2011) — A Monash student has made a breakthrough in the field of astrophysics, discovering what has until now been described as the Universe's 'missing mass'. Amelia Fraser-McKelvie, working within a team at the Monash School of Physics, conducted a targeted X-ray search for the matter and within just three months found it -- or at least some of it.

What makes the discovery all the more noteworthy is the fact that Ms Fraser-McKelvie is not a career researcher, or even studying at a postgraduate level. She is a 22-year-old undergraduate Aerospace Engineering/Science student who pinpointed the missing mass during a summer scholarship, working with two astrophysicists at the School of Physics, Dr Kevin Pimbblet and Dr Jasmina Lazendic-Galloway.The School of Physics put out a call for students interested in a six-week paid astrophysics research internship during a recent vacation period, and chose Ms Fraser-McKelvie from a large number of applicants. Dr Pimbblet, lecturer in the School of Physics put the magnitude of the discovery in context by explaining that scientists had been hunting for the Universe's missing mass for decades."It was thought from a theoretical viewpoint that there should be about double the amount of matter in the local Universe compared to what was observed. It was predicted that the majority of this missing mass should be located in large-scale cosmic structures called filaments -- a bit like thick shoelaces," said Dr Pimbblet.

http://www.sciencedaily.com/releases/2011/05/110524094515.htmAstrophysicists also predicted that the mass would be low in density, but high in temperature -- approximately one million degrees Celsius. This meant that, in theory, the matter should have been observable at X-ray wavelengths. Amelia Fraser-McKelvie's discovery has proved that prediction correct.Ms Fraser-McKelvie said the 'Eureka moment' came when Dr Lazendic-Galloway closely examined the data they had collected."Using her expert knowledge in the X-ray astronomy field, Jasmina reanalysed our results to find that we had in fact detected the filaments in our data, where previously we believed we had not."X-ray observations provide important information about physical properties of large-scale structures, which can help astrophysicists better understand their true nature. Until now, they had been making deductions based only on numerical models, so the discovery is a huge step forward in determining what amount of mass is actually contained within filaments.Still a year away from undertaking her Honours year (which she will complete under the supervision of Dr Pimbblet), Ms Fraser-McKelvie is being hailed as one of Australia's most exciting young students. Her work has been published in the Monthly Notices of the Royal Astronomical Society."Being a published author is very exciting for me, and something I could never have achieved without the help of both Kevin and Jasmina. Their passion and commitment for this project ensured the great result and I am very thankful to them for all the help they have given me and time they have invested," said Ms Fraser-McKelvie.Dr Pimbblet said that he had under his tuition a very talented student who excelled in performing the breakthrough research."She has managed to get a refereed publication accepted by one of the highest ranking astronomy journals in the world as a result of her endeavours. I cannot underscore enough what a terrific achievement this is. We will use this research as a science driver for future telescopes that are being planned, such as the Australian Square Kilometre Array Pathfinder, which is being built in outback Western Australian."

It’s the biggest piece of NASA space junk to fall to Earth in more than 30 years. It should create a light show. The satellite will partially burn up during reentry and, by NASA’s calculation, break into about 100 pieces, creating fireballs that should be visible even in daytime.

An estimated 26 of those pieces will survive the re-entry burn and will spray themselves in a linear debris field 500 miles long. The largest chunk should weigh about 300 pounds.

A: The partial solar eclipse will occur late in the day in Southern California on Sunday, beginning at 5:24 p.m., reaching its maximum coverage at 6:38 p.m., and exiting the sun's path at 7:42 p.m., just 10 minutes before sunset. "That means the sun is fairly low in the northwest, and you want a clear view of the northwest horizon," said Griffith Observatory director Ed Krupp.

He suggested a place with a clear view of the northwest, with an elevated view and a clear horizon, to see the moon obscure the sun's beams. Griffith Observatory, which is run by the city of Los Angeles, will have extra telescopes and staff on hand to help people view the eclipse for free.

"They'll be seeing something that is really unusual -- a big bite coming out of the sun. And that's the real charm of this event," Krupp said.

Q: How big of a bite will the moon's shadow take of the sun?

A: According to the Griffith Observatory, 86% of the sun's diameter will be covered up by the moon. (That statistic is the standard one astronomers like to use; lay people may prefer knowing that 79% of the area of the sun will be covered up.) "It's a pretty deep eclipse here in Los Angeles," Krupp said

Oct. 16, 2012: This artists impression made available by the European Southern Observatory shows a planet, right, orbiting the star Alpha Centauri B, center, a member of the triple star system that is the closest to Earth. Alpha Centauri A is at left. The Earth's Sun is visible at upper right. (AP)

WASHINGTON – European astronomers say that just outside our solar system they've found a planet that's the closest you can get to Earth in location and size.

It is the type of planet they've been searching for across the Milky Way galaxy and they found it circling a star right next door -- 25 trillion miles away. But the Earth-like planet is so hot its surface may be like molten lava. Life cannot survive the 2,200 degree heat of the planet, so close to its star that it circles it every few days.

The astronomers who found it say it's likely there are other planets circling the same star, a little farther away where it may be cool enough for water and life. And those planets might fit the not-too-hot, not-too-cold description sometimes call the Goldilocks Zone.

That means that in the star system Alpha Centauri B, a just-right planet could be closer than astronomers had once imagined.

It's so close that from some southern places on Earth, you can see Alpha Centauri B in the night sky without a telescope. But it's still so far that a trip there using current technology would take tens of thousands of years.

But the wow factor of finding such a planet so close has some astronomers already talking about how to speed up a 25 trillion-mile rocket trip there. Scientists have already started pressuring NASA and the European Space Agency to come up with missions to send something out that way to get a look at least.

The research was released online Tuesday in the journal Nature. There has been a European-U.S. competition to find the nearest and most Earthlike exoplanets -- planets outside our solar system. So far scientists have found 842 of them, but think they number in the billions.

While the newly discovered planet circles Alpha Centauri B, it's part of a system of three stars: Alpha Centauri A, B and the slightly more distant Proxima Centauri. Systems with two or more stars are more common than single stars like our sun, astronomers say.

This planet has the smallest mass -- a measurement of weight that doesn't include gravity -- that has been found outside our solar system so far. With a mass of about 1.1 times the size of Earth, it is strikingly similar in size.

Stephane Udry of the Geneva Observatory, who heads the European planet-hunting team, said this means "there's a very good prospect of detecting a planet in the habitable zone that is very close to us."

And one of the European team's main competitors, Geoff Marcy of the University of California Berkeley, gushed even more about the scientific significance.

"This is an historic discovery," he wrote in an email. "There could well be an Earth-size planet in that Goldilocks sweet spot, not too cold and not too hot, making Alpha Centauri a compelling target to search for intelligent life."

Oct. 16, 2012: This artists impression made available by the European Southern Observatory shows a planet, right, orbiting the star Alpha Centauri B, center, a member of the triple star system that is the closest to Earth. Alpha Centauri A is at left. The Earth's Sun is visible at upper right. (AP)

WASHINGTON – European astronomers say that just outside our solar system they've found a planet that's the closest you can get to Earth in location and size.

It is the type of planet they've been searching for across the Milky Way galaxy and they found it circling a star right next door -- 25 trillion miles away. But the Earth-like planet is so hot its surface may be like molten lava. Life cannot survive the 2,200 degree heat of the planet, so close to its star that it circles it every few days.

The astronomers who found it say it's likely there are other planets circling the same star, a little farther away where it may be cool enough for water and life. And those planets might fit the not-too-hot, not-too-cold description sometimes call the Goldilocks Zone.

That means that in the star system Alpha Centauri B, a just-right planet could be closer than astronomers had once imagined.

It's so close that from some southern places on Earth, you can see Alpha Centauri B in the night sky without a telescope. But it's still so far that a trip there using current technology would take tens of thousands of years.

But the wow factor of finding such a planet so close has some astronomers already talking about how to speed up a 25 trillion-mile rocket trip there. Scientists have already started pressuring NASA and the European Space Agency to come up with missions to send something out that way to get a look at least.

The research was released online Tuesday in the journal Nature. There has been a European-U.S. competition to find the nearest and most Earthlike exoplanets -- planets outside our solar system. So far scientists have found 842 of them, but think they number in the billions.

While the newly discovered planet circles Alpha Centauri B, it's part of a system of three stars: Alpha Centauri A, B and the slightly more distant Proxima Centauri. Systems with two or more stars are more common than single stars like our sun, astronomers say.

This planet has the smallest mass -- a measurement of weight that doesn't include gravity -- that has been found outside our solar system so far. With a mass of about 1.1 times the size of Earth, it is strikingly similar in size.

Stephane Udry of the Geneva Observatory, who heads the European planet-hunting team, said this means "there's a very good prospect of detecting a planet in the habitable zone that is very close to us."

And one of the European team's main competitors, Geoff Marcy of the University of California Berkeley, gushed even more about the scientific significance.

"This is an historic discovery," he wrote in an email. "There could well be an Earth-size planet in that Goldilocks sweet spot, not too cold and not too hot, making Alpha Centauri a compelling target to search for intelligent life."

Fascinating look at a new paper that charts planetary tidal influence upon the sun and then relates them to known terrestrial solar cycles. If true it ought to suggest to carbon fetishists that there are subtle and powerful influences on the earth's climate that transcend the single variable they obsess over.

Astronomers are keeping a wary eye on a large asteroid expected to narrowly miss hitting Earth next Friday in the closest known approach of a dangerous cosmic object since NASA started tracking such debris.

Next Friday, a 130,000 ton asteroid is set to pass perilously close to earth. WSJ's Robert Lee Hotz runs down what you need to know about the 2012 DA14.

National Aeronautics and Space Administration experts who plotted its trajectory are confident that the primordial rock, weighing an estimated 130,000 metric tons, will pass within "a remarkably close distance" of Earth, nearer than many orbiting communications satellites but far enough away to safely speed past the planet.

At its closest approach—a distance of about 17,200 miles or so away—the asteroid will pass over the eastern Indian Ocean, off Sumatra at 2:24 pm ET Friday, Feb. 15. It will be travelling eight times as fast as a bullet from a high-powered rifle. Depending on local weather, it may be visible from Eastern Europe, Australia and Asia, with binoculars or a moderately powered telescope, space-agency officials said.

"No Earth impact is possible," said asteroid expert Donald Yeomans at the Jet Propulsion Laboratory in Pasadena, Calif. The asteroid poses no danger to the 400 or so satellites in higher orbits around Earth, agency officials said.

Known officially as 2012 DA14, the asteroid is about 150 feet across and was discovered last February by astronomers at the La Sagra Sky Survey operated by the Astronomical Observatory of Mallorca in Spain.

In its journey through space, Earth is bombarded by a hailstorm of comets, meteors and asteroids. Most are motes that sparkle like fireflies as they burn up entering the atmosphere, about 100 tons worth each day. Others have had catastrophic consequences.

Highlighting the risks such asteroids pose to the planet, researchers at the University of California, Berkeley, on Thursday tightened the link between the demise of most dinosaurs 66 million years ago and the impact of a six-mile-wide asteroid that left a 110-mile-wide crater off the Yucatan coast of Mexico. On a geologic time scale, the two events occurred at virtually the same moment, according to new and more precise dating results that they reported in the journal Science.

All told, scientists at NASA's Jet Propulsion Laboratory estimate there are about 500,000 objects about the size of asteroid 2012 DA14 that regularly cross Earth's path. At least one object that size flies close to Earth about every 40 years and one likely hits the planet about once every 1,200 years, astronomers calculate.

They believe the impact of an asteroid that size would generate about 2.5 megatons of blast energy—about twice the explosive power of the B83 nuclear warhead currently deployed in the U.S. military arsenal.

A Warning From the Asteroid Hunters The likelihood in this century of an asteroid impact with 700 times the destructive power of the Hiroshima A-bomb: 30%..By ED LU AND MARTIN REES WSJ

In the game of cosmic roulette that is our solar system, we just got lucky. Earth will get a very close shave on Friday, Feb. 15, when Asteroid 2012 DA14 passes just 17,000 miles from our planet. That is less than the distance from New York to Sydney and back, or the distance the Earth travels around the sun in 14 minutes. We are dodging a very large bullet.

The people of Earth also are getting a reminder that even in our modern society, our future is affected by the motion of astronomical bodies. The ancients were correct in their belief that the heavens affect life on Earth—just not in the way they imagined. Sometimes those heavenly bodies actually run into Earth. That is why we must make it our mission to find asteroids before they find us.

The last major asteroid impact on Earth was on June 30, 1908, when one about the size of an office building (140 feet across) slammed into Siberia with a destructive energy 700 times that of the atomic bomb dropped on Hiroshima. That asteroid devastated a region roughly the size of the San Francisco Bay area. Asteroid 2012 DA14, which will be passing over our heads on Friday, is about the same size as the asteroid that devastated Siberia's Tunguska region.

Many wonder about the odds that an asteroid may hit Earth in their lifetime. As it turns out, that is something scientists can measure quite well. We can count asteroids passing near the Earth using telescopes. We can count the number of craters on the moon. And we can count shooting stars in the sky, which are just small asteroids burning up in our upper atmosphere. We know how often asteroids of different sizes hit the Earth—and the odds of a dangerous one are cause for reflection.

The chance of another Tunguska-size impact somewhere on Earth this century is about 30%. That isn't the likelihood that you will be killed by an asteroid, but rather the odds that you will read a news headline about an asteroid impact of this size somewhere on Earth. Unfortunately, that headline could be about the destruction of a city, as opposed to an unpopulated region of Siberia.

Enlarge Image

CloseNASA/JPL-Caltech/Associated Press

This image shows a simulation of asteroid 2012 DA14 approaching the Earth..The chance in your lifetime of an even bigger asteroid impact on Earth—with explosive energy of 100 megatons of TNT—is about 1%. Such an impact would deliver many times the explosive energy of all the munitions used in World War II, including the atomic bombs. This risk to humanity is similar to an individual's odds of dying in a car accident. That risk is small, but would you drive a car without air bags and seat belts? The question is apt because our society is effectively doing so with regard to the risk of a devastating asteroid strike.

The impact on Earth from a 3,000-foot-wide asteroid would cause an explosion equivalent to 40,000 megatons of TNT—and would likely end human civilization altogether, regardless of where it hit. The odds that such an asteroid impact would make us the last generation of human civilization are no lower than the odds of an average American dying in an earthquake (about 0.001%).

NASA has managed to find and track more than 90% of these major asteroids, so a civilization-ending impact in the next 100 years could come only from one of the undiscovered 10% of asteroids larger than 3,000 feet across. But smaller and more numerous asteroids remain a threat simply because we have mapped only a small percentage of them and therefore don't know if an impact is imminent.

We have the technology to deflect these asteroids—through small spacecraft known as kinetic impactors and gravity tractors that can change an asteroid's trajectory—but only if we have years of advance warning. We discovered 2012 DA14 only a year ago, so had it been on a collision course with Earth, there is nothing we could have done about it except evacuate the area near the expected impact site and hope for the best.

To defend ourselves, we first have to find and track the asteroids (like 2012 DA14) large enough to do great damage should they strike Earth. There are about one million such asteroids in dangerous orbits near Earth, yet scientists have identified the trajectories of less than 1% of them (fewer than 10,000). For every 2012 DA14 we know of, there are 99 more we know nothing about.

That is why the B612 Foundation was established in 2002 and since 2012 has been building the Sentinel Space Telescope to find threatening asteroids before they find us. It is part of the most ambitious and important private space mission in history. The Sentinel telescope will give humanity decades of warning before a future asteroid impact so we can employ space technology to protect the planet. Because this is a privately financed project, the general public can get involved in making Sentinel a success.

On most days, human civilization wins the game of cosmic roulette. But just as we take precautions to reduce our individual risks of dying in car accidents or earthquakes, we should be doing the same to reduce our societal risk of a catastrophic asteroid impact. Let's open our eyes and stop gambling with our future.

Mr. Lu, a former NASA astronaut, is CEO of the B612 Foundation in Mountain View, Calif. Lord Rees is astronomer royal of the U.K. and the author of "From Here to Infinity" (W.W. Norton, 2012).

"Because the moon's orbit around our planet is elliptical, its precise distance varies, depending on where it is in the orbit. It is rare to have the moon in perigee when it is Full.Therefore it will look about 10-15% larger but nearly 30% brighter on Sunday!"

Gravitational waves detected in the aftermath of the Big Bang suggest one universe just might not be enough..

An illustration of multiple universes.

This illustration depicts a main membrane out of which individual universes arise; they then expand in size through time.

ART BY MOONRUNNER DESIGN .

By Dan Vergano

National Geographic

Published March 18, 2014

Bored with your old dimensions—up and down, right and left, and back and forth? So tiresome. Take heart, folks. The latest news from Big Bang cosmologists offers us some relief from our humdrum four-dimensional universe.

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Gravitational waves rippling through the aftermath of the cosmic fireball, physicists suggest, point to us inhabiting a multiverse, a universe filled with many universes. (See: "Big Bang's 'Smoking Gun' Confirms Early Universe's Exponential Growth.")

That's because those gravitational wave results point to a particularly prolific and potent kind of "inflation" of the early universe, an exponential expansion of the dimensions of space to many times the size of our own cosmos in the first fraction of a second of the Big Bang, some 13.82 billion years ago.

"In most models, if you have inflation, then you have a multiverse," said Stanford physicist Andrei Linde. Linde, one of cosmological inflation's inventors, spoke on Monday at the Harvard-Smithsonian Center for Astrophysics event where the BICEP2 astrophysics team unveiled the gravitational wave results.

Essentially, in the models favored by the BICEP2 team's observations, the process that inflates a universe looks just too potent to happen only once; rather, once a Big Bang starts, the process would happen repeatedly and in multiple ways. (Learn more about how universes form in "Cosmic Dawn" on the National Geographic website.)

"A multiverse offers one good possible explanation for a lot of the unique observations we have made about our universe," says MIT physicist Alan Guth, who first wrote about inflation theory in 1980. "Life being here, for example."

Lunchtime

The Big Bang and inflation make the universe look like the ultimate free lunch, Guth has suggested, where we have received something for nothing.

But Linde takes this even further, suggesting the universe is a smorgasbord stuffed with every possible free lunch imaginable.

That means every kind of cosmos is out there in the aftermath of the Big Bang, from our familiar universe chock full of stars and planets to extravaganzas that encompass many more dimensions, but are devoid of such mundane things as atoms or photons of light.

In this multiverse spawned by "chaotic" inflation, the Big Bang is just a starting point, giving rise to multiple universes (including ours) separated by unimaginable gulfs of distance. How far does the multiverse stretch? Perhaps to infinity, suggests MIT physicist Max Tegmark, writing for Scientific American.

That means that spread across space at distances far larger than the roughly 92 billion light-year width of the universe that we can observe, other universes reside, some with many more dimensions and different physical properties and trajectories. (While the light from the most distant stuff we can see started out around 14 billion light-years away, the universe is expanding at an accelerating rate, stretching the boundaries of the observable universe since then.)

Comic Mismatches

"I'm a fan of the multiverse, but I wouldn't claim it is true," says Guth. Nevertheless, he adds, a multiverse explains a lot of things that now confuse cosmologists about our universe.

For example, there is the 1998 discovery that galaxies in our universe seem to be spreading apart at an accelerating rate, when their mutual gravitational attraction should be slowing them down. This discovery, which garnered the 2011 Nobel Prize in physics, is generally thought to imply the existence of a "dark energy" that counteracts gravity on cosmic scales. Its nature is a profound mystery. About the only thing we understand about dark energy, physicists such as Michael Turner of the University of Chicago have long said, is its name.

"There is a tremendous mismatch between what we calculate [dark energy] ought to be and what we observe," Guth says. According to quantum theory, subatomic particles are constantly popping into existence and vanishing again in the vacuum of space, which should endow it with energy—but that vacuum energy, according to theoretical calculations, would be 120 orders of magnitude (a 1 followed by 120 zeroes) too large to explain the galaxy observations. The discrepancy has been a great source of embarrassment to physicists.

A multiverse could wipe the cosmic egg off their faces. On the bell curve of all possible universes spawned by inflation, our universe might just happen to be one of the few universes in which the dark energy is relatively lame. In others, the antigravity force might conform to physicists' expectations and be strong enough to rip all matter apart.

A multiverse might also explain away another embarrassment: the number of dimensions predicted by modern "superstring" theory. String theory describes subatomic particles as being composed of tiny strings of energy, but it requires there to be 11 dimensions instead of the four we actually observe. Maybe it's just describing all possible universes instead of our own. (It suggests there could be a staggeringly large number of possibilities—a 1 with 500 zeroes after it.)

Join the "multiverse club," Linde wrote in a March 9 review of inflationary cosmology, and what looks like a series of mathematical embarrassments disappears in a cloud of explanation. In a multiverse, there can be more things dreamt of in physicists' philosophy than happen to be found in our sad little heaven and earth.

Life, the Universe, and Everything

The multiverse may even help explain one of the more vexing paradoxes about our world, sometimes called the "anthropic" principle: the fact that we are here to observe it.

To cosmologists, our universe looks disturbingly fine-tuned for life. Without its Goldilocks-perfect alignment of the physical constants—everything from the strength of the force attaching electrons to atoms to the relative weakness of gravity—planets and suns, biochemistry, and life itself would be impossible. Atoms wouldn't stick together in a universe with more than four dimensions, Guth notes.

If ours was the only cosmos spawned by a Big Bang, these life-friendly properties would seem impossibly unlikely. But in a multiverse containing zillions of universes, a small number of life-friendly ones would arise by chance—and we could just happen to reside in one of them.

"Life may have formed in the small number of vacua where it was possible, in a multiverse," says Guth. "That's why we are seeing what we are seeing. Not because we are special, but because we